If the feds can find another spot to try Khalid Shaikh Mohammed and four other accused terrorists, Bloomberg now wants them to go for it.

Bloomberg on 9/11 Trials

Bloomberg says the trials will cost a billion dollars and does wish the Feds would move them somewhere else. (Published Tuesday, Feb 2, 2010)

"It's up to the federal government ... but if they were to move it elsewheres I'd be very happy. But you'd have to ask them," Bloomberg said at a Q&A session Wednesday.

The mayor's support for an alternative location to hold the 9/11 terror trials marks a complete reversal from his sentiments last week, when he flatly rejected proposals to move the trial to the less trafficked, less populated Governor's Island.

Bloomberg's outright dismissal of the idea earned him reprimand from political players like Assembly Speaker Sheldon Silver. Silver accused him of being insensitive to the concerns of residents of Lower Manhattan who feared the implications of holding the trial Downtown.

But as projected security costs for the high-profile trial continue to escalate and the complex plan develops, Bloomberg appears to be reconsidering his options.

"The mayor supported the decision to hold the trial in lower Manhattan in principle, but the security plan has since been developed and the practical implications of that plan will have a real impact on downtown residents," Bloomberg spokesman Jason Post told NBC New York. "He therefore would support an alternate venue."

Police Commissioner Raymond Kelly initially estimated costs for the trial would run around $75 million. That estimate quickly upped to a whopping $250 million a year for as long as the suspects are detained in the city.

Now Bloomberg says costs could soar as high as $1 billion. He reached the staggering sum by multiplying the $250 million a year estimate by four, pointing out no one could know for sure how long the trials would last.

"It would be great if the federal government could find a site that didn't cost $1 billion, which using downtown will and it will also impact traffic, commerce and people's lifestyles downtown and it would be great if we didn't do it," Bloomberg said.

Ultimately, the decision is up to the federal government.

"The key thing here is that this is not the mayor’s decision; this is a decision to be made by the federal government," Post told NBC New York. "The city’s role would be to provide security outside the courtroom."

The mayor had backed the Obama's administration to hold the terror trials down the block from Ground Zero since Attorney General Eric Holder announced the decision in November. At the time, Bloomberg called it a "fitting location" and said he had confidence the NYPD could handle the additional security requirements.

Residents in Lower Manhattan banded together to battle the decision, arguing it could endanger their homes and hamper local business. Concerned citizens, led by Community Board 1, proposed the trial be moved to Governor's Island.

Kelly ordered an initial review of the viability of trying the five terror suspects on Governor's Island, but analysts determined it to be an unsuitable location.

"An NYPD initial review has found Governor’s Island an impractical alternative as a site for the trial of the 9/11 defendants, principally because of risks related to transporting the prisoners to and from the island, as well as the general lack of modern infrastructure there," Deputy Commissioner Paul Browne said in a statement last week.